I have made a extremely similar sour, the funktional fruit sour from NB and I did it with lactose and wlp 510 for the yeast. Its called a tart shake here when you add lactose to a sour and it tastes good. Not too sweet don’t worry about that. Recognize that when you add the fruit, all the sugar in it will be fermented so it will not be too sweet. I used blackberry puree rather than cherry. I also added pectinase with the puree.
It was so good that a taste panel of 4 selected this for one of the beers for my daughter’s wedding. They liked the fruit sour the best, kolsch second, coconut brown ale 3, ipa 4, dunkel bock last. I thought they were nuts for wanting a tart shake at a wedding as most people are not fond of sour beers even when sweetened with lactose.
Then they told me I had to do it without lactose as groom was allergic to that. I did that by raising mash to 156F (less fermentable sugars) then adding the puree after a 34 F cold crash so it would not ferment and be sweet. After it sat cold a while, I then filtered through a 5 micron filter to clarify it(40 psi delta P!). Kegged it and force carbonated it. No bottling done as that would make a bottle bomb.
sorry for rambling about this special beer.